Method and apparatus for using adaptive optics in a scanning laser ophthalmoscope

Abstract

A scanning laser ophthalmoscope incorporates adaptive optics to compensate for wavefront aberrations in the eye. Light from a light source is scanned onto the retina. Light reflected from the retina is detected for imaging and is also used for wavefront sensing. The sensed wavefront aberrations are used to control an adaptive optic device, such as a deformable mirror, disposed in the path of the light from the source in order to compensate for the aberrations.

Description

REFERENCE TO RELATED APPLICATION [0001] The present application claims the benefit of U.S. Provisional Application No. 60 / 316,173, filed Aug. 30, 2001, whose disclosure is hereby incorporated by reference in its entirety into the present disclosure.STATEMENT OF GOVERNMENT INTEREST [0002] The present invention was developed under NIH Grant No. R1 EY 13299-01 and NSF Grant No. AST 9876783. The government has certain rights in the invention.FIELD OF THE INVENTION [0003] The present invention is directed to scanning laser ophthalmoscopes (SLO) and methods of using them, and more particularly to such ophthalmoscopes and methods of using them which involve the use of adaptive optics (AO) to compensate for wavefront aberrations in the eye under examination. DESCRIPTION OF RELATED ART [0004] The development of ocular imaging has progressed since the first scanning laser ophthalmoscope (SLO) was disclosed in U.S. Pat. No. 4,213,678. The first patent relating to imaging the ocular fundus whil...

AI Technical Summary

Benefits of technology

This approach significantly improves the lateral resolution by up to three times and axial resolution by up to 10 times compared to conventional SLOs, reducing non-common path errors and enhancing image contrast by suppressing scattered light from out-of-focus planes.

Problems solved by technology

A scanning laser ophthalmoscope for high lateral-resolution imaging was developed which was capable of imaging a living human eye but did not use adaptive optics (AO) and had limited resolution at the microscopic level.

A 14, 2884-2892 (1997), used an ophthalmoscope equipped with AO to image microscopic structures in the retina, but they did not apply the technology to a SLO.

Although there are a number of patents covering SLO's, they do not propose a method for wavefront sensing whereby the light path is scanned / descanned using the same optics and light source as that used for imaging the ocular fundus.

Methods that do not use the same optics for wavefront sensing and light detection are subject to a common phenomena called “non-common path errors,” where the aberrations on the path to the wavefront sensor are different than those reaching the light detector for imaging.

However, areal imaging techniques are limited in that they cannot suppress light from layers in front of or behind the focal plane of the ophthalmoscope.

Because of this limitation, the images may have high resolution, but will suffer from low contrast because of scattered light from structures outside of the best focal plane.

To date, there has been no successful application of AO into a SLO.

Bille's above-cited patent describes a design for a SLO that integrates a wavefront sensor into the design, but it does not use the same path as the light detection path and is therefore subject to the problem of non-common path errors.

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